Cephalosporin semi-synthetic antibiotics substituted by an amino group in the 3-position of the 3-cephem ring system have been described by Spry, U.S. Pat. No. 4,001,226. Also described by Spry are 3-isocyanato, 3-azidocarbonyl, and 3-(substituted amino)carbonyl 3-cephem acids and esters.
In copending application Ser. No. 536,468 filed Sept. 28, 1983 (now U.S. Pat. No. 4521598), Spry and Spitzer describe 3-azido-3-cephem semi-synthetic antibiotics and the conversion thereof to 4,7-bicyclic diazabicyclononene antibiotic compounds. It has been found that the 3-azido-3-cephem compounds react with cyclic and acyclic vinyl ethers and with acyclic enamines to form, respectively, 3-cephem-3-imidates and 3-cephem-3-amidines wherein the nitrogen of the imidate and one nitrogen of the amidine group is bonded to the C3 carbon. Cyclic enol ethers and cyclic enamines react with the 3-cephem-3-azido compounds to provide bicyclic aziridines.